On Thursday, February 21, 2019 at 1:35:17 PM UTC-7, Brent wrote: > > > > On 2/21/2019 5:27 AM, [email protected] <javascript:> wrote: > > > > On Wednesday, February 20, 2019 at 7:50:51 PM UTC-7, Brent wrote: >> >> >> >> On 2/20/2019 1:23 PM, [email protected] wrote: >> >> >> >> On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote: >>> >>> >>> >>> On 2/20/2019 8:42 AM, [email protected] wrote: >>> >>> >>> >>> On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John Clark wrote: >>>> >>>> >>>> >* Newton "explained" * >>>> >>>> >>>> Why did you put explained in quotation marks? If you can predict what >>>> something is going to do then you've explained it, the better the >>>> prediction the better the explanation. I don't know what else the word >>>> could possibly mean. And in science no explanation is perfect, but some >>>> are >>>> less wrong than others. >>>> >>> >>> *QM better illustrates the justification for quotes. Many >>> interpretations that make the same predictions. AG * >>> >>>> >>>> *> why a body at "rest" can start moving, via the application of >>>>> "force"* >>>> >>>> >>>> And Einstein explained that a body moving in a geodesic through 4D >>>> spacetime will take a path that is not a geodesic if a force is applied. >>>> The Earth is moving in a straight line (aka a geodesic) through curved >>>> spacetime; the reason Earth's orbit looks elliptical to us is due to map >>>> distortion, the same reason that in a flat map of the curved surface of >>>> the >>>> Earth Greenland looks larger than South America and is almost as large as >>>> Africa. Except that it's even worse, in one we're projecting the 2 D >>>> curved surface of the Earth into the flat 2D surface of the map, but with >>>> Einstein we're projecting a curved 4D volume into a flat 3D volume. >>>> >>>> *> What does "rest" mean in GR * >>>> >>>> >>>> In General Relativity moving in a geodesic is as close as you can get >>>> to the traditional idea of rest, but as long as time passes you're going >>>> to >>>> be moving through 4D spacetime. >>>> >>> >>> >>> *If you're at spatial rest in spacetime in the presence of a >>> gravitational source, how does GR explain the subsequent spatial motion? AG >>> * >>> >>> >>> When you were at "spatial rest" you had a force applied to you. >>> Removing it allowed you to follow a geodesics path through >>> spacetime....also known as "falling". >>> >>> Brent >>> >>> >> >> *So it seems that GR doesn't explain motion; rather, it assumes motion is >> a natural state of things. AG * >> >> >> So called "standing still" is just motion in the time direction only...in >> Newtonian and special relativity as well. Just as there is no absolute >> motion, there's no absolution motionless either...it's called "relativity" >> for a reason. >> >> Brent >> > > > *Other than gravity, the remaining known forces are moderated, or shall we > say "caused by" particles. Doesn't GR remain an exception; that is, > wouldn't it preclude the existence of a graviton? TIA, AG * > > > Gravitons, the weak-field limit quanta of the gravitational field, aren't > precluded. They are implicit in string-theory; which is why string theory > is a candidate for the quantum theory of gravity. The problem is there's > no mathematically consistent way to extend the graviton, weak field, > picture to the strong field limit and predict what happens in a black hole > where GR predicts a singularity. > > Brent >
*ISTM that gravitons would be inconsistent with GR, which derives gravitating motion from geometry, not mediating particles. AG* > > > >> >> >>>> *> what causes "motion" from that pov?* >>>> >>>> >>>> Force, same as with Newton. >>>> >>>> John K Clark >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/everything-list. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
